Monolithic coil components, for example, as described in Japanese Examined Patent Application Publication No. 63-44286 (Patent Document 1), are a typical example of monolithic ceramic electronic components including therein a coil conductor extending in a coil shape. In the case of producing a monolithic coil component, a step of producing an unfired component body by forming a coil conductor on a surface of a magnetic or insulating ceramic green sheet, stacking a plurality ceramic green sheets in such a manner that one end of the coil conductor is connected to another coil conductor via a hole arranged in the ceramic green sheet and press-bonding the plurality of ceramic green sheets; and a step of firing the unfired component body are performed. The above-mentioned coil conductors are formed on surfaces of ceramic green sheets by printing using conductive paste.
Thus, according to the technique described in Patent Document 1, in the unfired component body, there are differences in thickness and density between a portion of a ceramic green sheet where a coil conductor is formed and a portion of the ceramic green sheet where a coil conductor is not formed. When the component body is fired, a difference in the contraction behavior occurs between the portion where the coil conductor is formed and the portion where the coil conductor is not formed. Thus, cracking may occur in the component body and the coil conductor may be broken.
Furthermore, according to the technique described in Patent Document 1, in the step of stacking the plurality of ceramic green sheets and press-bonding the plurality of ceramic green sheets, the possibility of displacement, deformation, and breaking of the coil conductors is concerned.
In order to solve the above-mentioned problems, for example, Japanese Unexamined Patent Application Publication No. 10-12455 (Patent Document 2) suggests that a coil conductor is formed by arranging a punched groove in a ceramic green sheet and filling the punched groove with conductive paste.